Chapter 1

Levels of organization

Chemical level, cellular level, tissue level, organ level, organ system level, organism level

Where do diseases begin

On the cellular level, with disruption of cell structure and function

Plasma membrane

Barrier between external and internal cell environment

Cellular edema

NA-K pumps fail

abnormal fluid build up in cells

Cellular dehydration

water moves out of cells and into surrounding fluid

Glycoproteins example

antigens

Glycoproteins function

Self vs non-self recognition

Glycoproteins play a role in blanks

Allergies

autoimmune diseases

transplant rejection

blood transfusion reactions

Sodium Potassium Pump Ion movement

3 Na+ out of cell

2 K+ into cell

Active transport requirements

needs ATP

Sodium-Potassium Pump Implications

Establishes resting membrane potential

Maintains fluid volume

Drugs can alter pump activity

Example of a drug that alters NA/K pump activity

Cardiac glycosides

Mitochondria metabolism type

Aerobic metabolism, usually forms free radicals

Free radicals

unstable atoms or molecules with an unpaired electron

Where are higher concentrations of mitochondria

highly active tissue

Aerobic metabolism

Glucose to pyruvate, which enters Krebs cycle

Net yield: 34 ATP

aerobic metabolism net yield

34 ATP

Anaerobic metabolism

Oxygen not available (hypoxia)

Glucose to pyruvate to lactic acid(can alter PH)

Anaerobic metabolism net yield

2 ATP

Mitochondrial DNA

Distinctive

Derived maternally

Enables study of maternal heritage

Lysosomes

Small organelles, contain digestive enzymes

Autolysis

cell death

Lysosomes release enzymes to destroy cell

Heterolysis

Digest foreign material

Lack of lysosomal enzymes and diseases

leads to the accumulation of harmful substance

Tay-Sachs disease

lack of lysosomal enzymes leading to ganglioside accumulation

Gangliosides

Fatty molecules are usually digested by lysosomes; accumulation can kill important cells

Proteasomes

Degrade proteins and polypeptide chains

cachexia

severe wasting syndrome that causes extreme muscle and weight loss

Accelerated proteasome activity is associated with this

Peroxisomes

Break down free radicals and long chain fatty acids

Adrenoleukodystrophy

Dysfunctional peroxisomes

Long-chain fatty acids accumulate in nervous system

Endoplasmic Reticulum

Network of tubules which acts as transport system

Smooth vs rough ER

Smooth: lipids

rough: proteins

ER stress may play a role in

cancer

obesity

diabetes

Ribosomes

Contain ribosomal RNA

Some are in rough ER

protein factories

Golgi Apparatus

Processes, packages, and secretes proteins

Receives protein from ER

Stores complete hormones in secretory vesicles, for release

Examples of hormones stored in secretory vesicles by golgi

ACTH

Insulin

Example of Protein Processing:ACTH

preprohormone=>ER(converts to prohormone)=>golgi(converts to real hormone)=>secretion

Secretory vesicles

formed by ER-Golgi systems

Contain substances to be secreted by the cell

Microtubules

Hollow filaments

Help with cell division, intracellular transport

Microfilaments

Solid, flexible fibers

Help with cell movement, found in muscle cells

Nucleus

contains genetic material(DNA)

DNA composition

Composed of nucleotides(purines and pyrimidines)

Purines

Adenine and guanine

Pyrimidines

cytosine and thymine

What replicates a DNA strand?

DNA polymerase

Transcription

DNA into messenger RNA

Translation

mRNA converted into amino acid sequence

ribosomes

transfer RNA

Codon

3-nucleotide sequence which codes a specific amino acid

Mitochondrial diseases clinical concept

Worse in brain cells, neurons, muscle cells

Proteasomes clinical concept

Cancer cachexia

Ribosomes clinical concept

target of some antibiotics